Sharp LL-T15S1 (serv.man7) Service Manual ▷ View online
A
Screen does not operate normally.
Check RGB cable.
Defective
Replace RGB cable with
a new one.
a new one.
Check screen condition by changing display modes.
Reset the microprocessor to check if screen condition changes.
(Press and hold MENU and SELECT buttons while turning on power switch.)
(Press and hold MENU and SELECT buttons while turning on power switch.)
Screen stays in black.
Screen stays in white.
Screen jitters or on-screen
characters flicker.
characters flicker.
Abnormal color
Check the following signals
1) Check if module control signal is output.
2) Check if gate voltage is output normally.
3) Check if Source voltage is output normally.
Yes
No
Yes
No
Yes
No
CLOCK and PHASE
can be adjusted?
can be adjusted?
Does abnormal area move on
screen when BLACK LEVEL or
CONT is changed after H-POS
or V-POS is set?
screen when BLACK LEVEL or
CONT is changed after H-POS
or V-POS is set?
Switch PWB defective
Main PWB defective.
LCD panel defective.
<Voice output error>
+12 V DC at 1st and 2nd pins of JP1?
Signal input of 4th pin of U12 is at H level
(+5 V DC)?
(+5 V DC)?
Check mute input circuit of I/F board.
Input signal of 3rd and 5th pins of U12 is normal?
Check power supply, vo ice input and voice
input circuit of I/F board.
input circuit of I/F board.
Signal input at 1st and 7th pins of U12 changes
when voice volume is changed.
when voice volume is changed.
Check control PWB and the volume circuit
around U11.
around U11.
Signal output at 8th, 10th, 11th and 13th pins of
U12 is normal?
U12 is normal?
Check amplifier circuit around U12.
Check speakers and speaker cables.
• Check connection of JP1 connector.
• Check fuse F1 of Power Jack PWB.
• Check fuse F1 of Power Jack PWB.
<Voice output error>
+12 V DC at 1st and 2nd pins of JP1?
Signal input of 4th pin of U12 is at H level
(+5 V DC)?
(+5 V DC)?
Check mute input circuit of I/F board.
Input signal of 3rd and 5th pins of U12 is normal?
Check power supply, vo ice input and voice
input circuit of I/F board.
input circuit of I/F board.
Signal input at 1st and 7th pins of U12 changes
when voice volume is changed.
when voice volume is changed.
Check control PWB and the volume circuit
around U11.
around U11.
Signal output at 8th, 10th, 11th and 13th pins of
U12 is normal?
U12 is normal?
Check amplifier circuit around U12.
Check speakers and speaker cables.
• Check connection of JP1 connector.
• Check fuse F1 of Power Jack PWB.
• Check fuse F1 of Power Jack PWB.
<Voice output error>
+12 V DC at 1st and 2nd pins of JP1?
Signal input of 4th pin of U12 is at H level
(+5 V DC)?
(+5 V DC)?
Check mute input circuit of I/F board.
Input signal of 3rd and 5th pins of U12 is normal?
Check power supply, vo ice input and voice
input circuit of I/F board.
input circuit of I/F board.
Signal input at 1st and 7th pins of U12 changes
when voice volume is changed.
when voice volume is changed.
Check control PWB and the volume circuit
around U11.
around U11.
Signal output at 8th, 10th, 11th and 13th pins of
U12 is normal?
U12 is normal?
Check amplifier circuit around U12.
Check speakers and speaker cables.
• Check connection of JP1 connector.
• Check fuse F1 of Power Jack PWB.
• Check fuse F1 of Power Jack PWB.
Display